Hi all. i'll hope someone can help me out here??

Some days ago, they installed here telenet or cable for 2 pc's, ik installed 2 same networkcards in 2 differents pc's. I installed winxp pro sp1, with a serial i get true news.binaries. (hacked one,black one)
No problem at first.
So i installed with the same disk, winxp pro sp1 on anther pc, both are connected true a hub, so i can surf the internet separated.
1ste problem came up: the serial number that i used on the 1ste pc didn't work on the other pc. So i'll brows true the newsgroups again and find another key, and it worked just fine.
2de problem came up: Not even a problem on my second pc, everything works fine here, but at the other pc, i have this weird download problem??

Surfing is no problem, it is even very fast. But I can't download exe files, sometimes i can download zip files. I cannot download from ftp sites, from download.microsoft.com, files from tucows, files from my own internet provider and more. I can't do update from windows, because it will not download from that site. I don't have problems using easynew.com, ik can download every file from there, but my pc is blocking the rest of the net (only download, not surfing).
I tried to installed netscape, but the same problem there.
Another problem is if i get e-mails, with exe or rar or zip, or eml, htm, and other, i cannot open them, because the are blokked..I didn't installed a virusscanner, or download manager or stuf like that, i did this for scanning for virussus but no virus on my pc. so i removed the virusscanner again.
I installed windowsXP again, after formatting in NTFS again, same problem, and again, in fat32, same problem, i installed winxp pro 1 edition, same problem...

The weird thing is that i can do that all on the other pc without any problem.

There is one thing, that i do last week, ik flashed my bios to the last version, but i don't think this is the problem.

Is there any prof or good god that can help me with this...i''ll hope so.